Dynamical time division duplex uplink and downlink configuration in a communications network

ABSTRACT

Lformat Y is equal to a payload size of the DCI format Y, and M is a number of bits of each configuration indication field. The eNB can map the DCI format Y onto the PDCCH. The eNB can transmit to the UE the PDCCH with a cyclic redundancy check (CRC) scrambled by an enhanced interference mitigation and traffic adaptation (eIMTA) Radio-Network Temporary Identifier (RNTI) for the UE.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/456,125 filed Mar. 10, 2017 with attorney docket number P63597C2,which is a continuation of U.S. patent application Ser. No. 15/256,105filed Sep. 2, 2016 with attorney docket number P63597C, which is acontinuation of U.S. patent application Ser. No. 14/247,675, filed Apr.8, 2014 with attorney docket number P63597, which claims the benefit ofreference U.S. Provisional Patent Application Ser. No. 61/859,121 filedJul. 26, 2013 with attorney docket number P59845Z, each of which areincorporated by reference herein.

BACKGROUND

In wireless communications systems downlink and uplink transmissions maybe organized into two duplex modes: frequency division duplex (FDD) modeand time division duplex (TDD) mode. The FDD mode uses a paired spectrumwhere a gap in frequency domain is used to separate uplink (UL) anddownlink (DL) transmissions. In TDD systems, an unpaired spectrum may beused where both UL and DL are transmitted over the same carrierfrequency. The UL and DL are separated in non-overlapped time slots inthe time domain.

Third generation partnership project (3GPP) long term evolution (LTE)TDD homogeneous systems operate synchronously in order to avoid UL/DLinter-cell interference between base stations or nodes, such as enhancedNode Bs (eNode Bs) and/or mobile terminals, such as user equipment(UEs). A geographic region served by an eNode B is commonly referred toas a cell. Cells in a network typically use the same UL/DL configurationfor synchronous operation of the LTE-TDD homogeneous systems. The UL/DLconfiguration includes frame configuration and UL/ DL resourceallocation within one radio frame. Additionally, the network can use theUL/DL configuration to align frame transmission boundaries in time. Thesynchronous operation can be effective to mitigate interference.However, the synchronous operation is not optimized for trafficadaptation and can significantly degrade packet throughput for smallcells in a heterogeneous network (HetNet).

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the disclosure will be apparent from thedetailed description which follows, taken in conjunction with theaccompanying drawings, which together illustrate, by way of example,features of the disclosure; and, wherein:

FIG. 1 depicts a multiple Radio Access Technology (RAT) heterogeneousnetwork (HetNet) with a macro cell overlaid with layers of lower powernodes in accordance with an example;

FIG. 2a illustrates of a uplink/downlink (UL/DL) subframe separated inthe frequency domain for a frequency division duplex (FDD) mode inaccordance with an example;

FIG. 2b illustrates of UL/DL subframes sharing a carrier frequency in atime division duplex (TDD) mode in accordance with an example;

FIG. 3A depicts a downlink control information (DCI) format for a singlecomponent carrier (CC) supporting dynamic UL/DL reconfiguration inaccordance with an example;

FIG. 3B depicts a DCI format for a multi-CC supporting dynamic UL/DLreconfiguration in accordance with an example;

FIG. 4 depicts a DCI format X that can be used to indicate a TDD UL/DLconfiguration in accordance with an example;

FIG. 5 depicts a DCI format for UUDL configuration indications inaccordance with an example;

FIG. 6 shows a table depicting a coding of 3-bit target cell identity(TCI) code words used for TDD UL/DL configuration indication inaccordance with an example;

FIG. 7 shows a table depicting a coding of 2-bit TCI code words used forTDD UL/DL configuration indication in accordance with an example;

FIG. 8 illustrates a signaling flow between a user equipment (UE) and aEUTRAN to establish a dynamic UL/DL configuration in accordance with anexample;

FIG. 9 illustrates a signaling flow between a UE and a evolved universalterrestrial radio access network (EUTRAN) to establish a dynamic UL/DLconfiguration in accordance with an example;

FIG. 10 illustrates a physical downlink control channel (PDCCH) that canbe used for a DCI format X transmission in accordance with an example;

FIG. 11 illustrates a common search space (CSS) on a PDCCH can be usedfor transmission of a DCI format X in accordance with an example;

FIG. 12 illustrates a DCI format X that includes a UL/DL configurationindication field in accordance with an example;

FIG. 13 illustrates a DCI format X that includes a UL/DL configurationindication field in accordance with an example;

FIG. 14 illustrates a subset of aggregation levels on primary cell(PCell) in accordance with an example;

FIG. 15 illustrates an enhanced physical downlink control channel(EPDCCH) physical resource block (PRB) set that is configured to beshared by all UEs that are configured with EPDCCH monitoring inaccordance with an example;

FIG. 16 illustrates a TDD UL/DL configuration supporting for cooperativemultiple point (CoMP) Scenario 4 in accordance with an example;

FIG. 17 illustrates a table with the configurations for the TDD UL/DLreconfiguration indication in accordance with an example;

FIG. 18 illustrates a UL/DL configuration in a CoMP Scenario 3 inaccordance with an example;

FIG. 19 illustrates a table of configurations for TDD UL/DLreconfiguration indication in accordance with an example;

FIG. 20 depicts the functionality of a computer circuitry with a UEoperable to dynamically change an UUDL configuration in a communicationsnetwork in accordance with an example;

FIG. 21 depicts the functionality of another computer circuitry with anenhanced Node B (eNode B) operable to dynamically change a TDD UL/DLconfiguration in a communications network in accordance with an example;

FIG. 22 illustrates a method for dynamically changing an UL/DL ratio ina communications network in accordance with an example; and

FIG. 23 illustrates a diagram of a UE in accordance with an example.

Reference will now be made to the exemplary embodiments illustrated, andspecific language will be used herein to describe the same. It willnevertheless be understood that no limitation of the scope of theinvention is thereby intended.

DETAILED DESCRIPTION

Before the present invention is disclosed and described, it is to beunderstood that this invention is not limited to the particularstructures, process steps, or materials disclosed herein, but isextended to equivalents thereof as would be recognized by thoseordinarily skilled in the relevant arts. It should also be understoodthat terminology employed herein is used for the purpose of describingparticular examples only and is not intended to be limiting. The samereference numerals in different drawings represent the same element.Numbers provided in flow charts and processes are provided for clarityin illustrating steps and operations and do not necessarily indicate aparticular order or sequence.

Mobile devices are increasingly equipped with multiple radio accesstechnologies (multi-RAT) that can connect to and choose among thedifferent types of radio technologies, including cellular technologiesthat use licensed portions of the radio spectrum, and wireless localarea network (WLAN) and personal area network (PAN) technologies thattypically use unlicensed portions of the radio spectrum.

In homogeneous networks, a base station or macro node can provide basicwireless coverage to mobile devices within the node coverage (i.e. thecell). Heterogeneous networks (HetNets) were introduced to handle theincreased traffic loads on the macro nodes due to increased usage andfunctionality of mobile devices.

A HetNet can be comprised of multiple types of radio access nodes and/orradio access technologies in a wireless network. HetNets can includemacro nodes, such as enhanced node Bs (eNBs) or base stations (BSs),overlaid with layers of small nodes or cells, such as micro-nodes,pico-nodes, femto-nodes, home-nodes, relay stations, WiFi access points(APs), and so forth. The small nodes, also referred to as low powernodes, can be deployed in a non-uniform or uncoordinated manner withinthe coverage area of the macro nodes (i.e. the cell). The macro nodescan be used for basic coverage, and the small nodes can be used to fillcoverage holes, to improve capacity in hot-zones or at the boundariesbetween the coverage areas of the macro nodes, and improve indoorcoverage where building structures impede signal transmission. FIG. 1depicts a multi-RAT HetNet in a macro-cell 110 with a macro-node 120overlaid with layers of lower power nodes or small nodes includingmicro-nodes 130, pico-nodes 140, femto-nodes 150, and WiFi APs 160 orother types of WLAN nodes or PAN nodes.

High demand for increased throughput by UEs can be satisfied bydeploying a cluster of small nodes to provide an acceptable quality ofservice (QoS) for the UEs. In one embodiment, dense clusterization ofsmall nodes can be used at hotspots for providing closer serving nodesto more UEs for increased network capacity. As the number of small nodesdeployed in a given area increases, the inter-small node interferencecan increase. As inter-small node interference reaches a thresholdlimit, there is an upper bound constraint on the number of small nodesthat can be deployed in a hotspot area.

Traditionally, the disadvantage of the high density deployment orclusterization of small nodes is the level of inter-small nodeinterference, e.g. the level of interference that occurs betweenmultiple small nodes in a dense area. The inter-small node interferencedecreases the signal to noise ratio (SNR) and/or the signal tointerference plus noise ratio (SINR) between UEs and small nodes,resulting in lower or decreased UE throughput.

In a wireless communications system, such as a third generationpartnership project (3GPP) long term evolution (LTE) system, downlink(DL) and uplink (UL) transmissions can be organized into two duplexmodes: frequency division duplex (FDD) mode and time division duplex(TDD) mode. An FDD mode can use a paired spectrum where a gap infrequency domain is used to separate uplink (UL) transmissions fromdownlink (DL) transmissions. FIG. 2A illustrates of a UL and DL subframeseparated in the frequency domain for the FDD mode. In TDD systems, anunpaired spectrum may be used where both UL and DL are transmitted overthe same carrier frequency. The UL transmissions and DL transmissionsare separated in the non-overlapping time slots in the time domain. FIG.2B illustrates UL and DL subframes sharing a carrier frequency in theTDD mode. As used herein, the term UL/DL is intended to refer to theuplink and the downlink.

A wireless communications system can operate synchronously in order toavoid UL/DL inter-cell interference between base stations, such as eNodeBs and/or mobile terminals, such as UEs. Cells in a wirelesscommunications system can use the same UL/DL configuration for asynchronous operation of the wireless communications system. The UL/DLconfiguration can include a frame configuration and UL/DL resourceallocations.

The usage of a same frame configuration in a HetNet deployment scenariocan degrade a quality of service (QoS) for a UE in the communicationsnetwork. Data traffic in HetNet scenarios can vary over time domains orcell domains. For example, a selected set of cells can have varieddominant traffic in either the DL transmission direction or the ULtransmission direction over time. The dominant traffic transmissiondirection can use more spectrum resources than the non-dominanttransmission direction to improve the QoS and systematic throughputperformance for a lower or medium traffic load. In HetNet deploymentscenarios, because small cells are closer in proximity to the end users,the level of isolation between eNode Bs is higher so that a largeportion of eNode Bs can be considered isolated cells. Isolated cells arecells with small nodes that create relatively low levels of inter-cellinterference with other small nodes in a macro cell.

In one embodiment, each small node in the isolated cells can dynamicallyconfigure or reconfigure the UL/DL configuration of the small node toadapt to changing real time data traffic conditions or instantaneousdata traffic conditions within the serving cell. In another embodiment,each small node in isolated cells can dynamically configure orreconfigure the UL/DL configuration of the small node by using cyclicredundancy check (CRC) parity bits scrambled with a TDD-Config-RNTIassigned for eIMTA operation. In one embodiment, signaling options suchas a system information block (SIB), paging, a radio resource control(RRC), medium access control (MAC) signaling, and/or L1 signaling can beused for support of UL/DL reconfiguration in different trafficadaptation time scales. For example, L1 signaling can be used for UL/DLreconfiguration as a robust signaling option with lower control overheadand shorter latency.

In one embodiment, blinding decoding can be used with selected signalingoptions, such as L1 signaling. In another embodiment, a DCI format, suchas a physical downlink control channel (PDCCH), can be used to signal acarrier-independent UL/DL configuration information for each servingcell. FIGS. 3A & 3B illustrate DCI formats used to indicate acarrier-independent UL/DL configuration. The DCI formats, such as PDCCH,in FIGS. 3A & 3B include TDD UL/DL Configuration Indicator Fields (CIFs)for selected UUDL configuration. FIG. 3A depicts a DCI format, such asPDCCH, for a single component carrier (CC) supporting dynamic UL/DLreconfiguration. FIG. 3B depicts a DCI format, such as PDCCH, used for amulti-CCs supporting dynamic UL/DL reconfiguration. In one embodiment, aDCI format can be used for a CoMP scenario 4 to achieve independentUL/DL configuration for each Transmission Point (TP).

In one embodiment, the network can be configured to order a DCI signalfor traffic adaption in a TDD system. In one embodiment, a unified DCIformat for carrying UL/DL configuration information can be dynamicallyupdated and transmitted at selected time intervals. For example, the DCIformat can be dynamically updated every 10 millisecond. In anotherembodiment, the DCI format can enable independent UL/DL configurationfor each serving cell in for selected deployment scenarios. The selecteddeployment scenarios can include: a single carrier scenario; acooperative multiple point (CoMP) scenario, such as CoMP scenario 3 or aCoMP scenario 4; a carrier aggregation (CA) scenario; and a CoMPscenario with CA enabled on remote radio heads (RRHs), such as acombination of CA and CoMP scenario.

FIG. 4 illustrates a new DCI format X, such as PDCCH, that can be usedto indicate a TDD UL/DL configuration with an M-bit TDD UL/DLconfiguration indicator field (CIF), used to indicate a UL/DLconfiguration. In one embodiment, M can designate a number or a literal.The X of the DCI format X can designate a number or a literal. A DCIformat X can carry TDD UL/DL configurations of multiple serving cellssimultaneously. In one embodiment, the DCI format can be transmitted onall fixed DL subframes, i.e. subframe 0, subframe 1, subframe 5, andsubframe 6. In another embodiment, the DCI format can be transmitted ona subset of the fixed subframes. In another embodiment, the DCI formatcan be transmitted on all DL subframes, including both fixed DLsubframes and flexible subframes. One advantage of transmitting the DCIformat on all DL subframes can be to enable a discontinuous reception(DRX) UE to acquire an actual UL/DL configuration being used by theeNode B when the DRX UE wakes up in a flexible subframe.

In one embodiment, the DCI format X can include a set of TDD UL/DLConfiguration Indicator (TCI) fields 1, 2, . . . , N, where N issignaled by the eNode B within RRC signaling for each eIMTA-enabled UE.In another embodiment, the DCI format X can include a set of TDD UUDLConfiguration Indicator (TCI)

${N = \left\lfloor \frac{L_{{format}\mspace{14mu} Y} - R_{others}}{M} \right\rfloor},$

fields 1, 2, . . . , N, where N can calculated by the UE using whereL_(format Y) is equal to the payload size of one of an existing DCIformat Y before cyclic redundancy check (CRC) attachment, format Y ismapped onto the common search space (CSS) (wherein the payload size ofthe DCI format size includes any padding bits appended to format Y), andR_(others)≥0 is a number of information bits used for other selectedapplications. In one embodiment, the selected applications can betransmission power control (TPC) commands for physical uplink sharedchannel (PUSCH) transmission on flexible subframes.

In one embodiment, when the total bits number of N TCI fields is lessthan the selected DCI format size Y on CSS or

${\left\lfloor \frac{L_{{format}\mspace{14mu} Y} - R_{others}}{M} \right\rfloor < \frac{L_{{format}\mspace{14mu} Y} - R_{others}}{M}},$

where

$\left\lfloor \frac{L_{{format}\mspace{14mu} Y} - R_{others}}{M} \right\rfloor$

rounds down to the nearest integer. For example, └2.3┘=2. In oneembodiment, when L=17, R=0, and M=3, then └L/3┘=5<5.7 and 2 bits can beappended for DCI format X aligned with DCI format Y size: 17 bitsbesides 5 3-bit TCI fields.

In one embodiment, information bit(s) with a predefined value of either0 or 1 can be appended to DCI format X until the payload size equalsthat of a DCI format Y. In one embodiment, the information bits can beappended to a DCI format X until the payload size of the DCI format Xequals a payload size of the DCI format Y, where the number of bits ofthe DCI format Y is bandwidth-dependent. FIG. 5 illustrates an exemplaryembodiment of the DCI format for UL/DL configuration indications. In oneembodiment, the DCI format Y can be a DCI format 0/1A/3/3A that can betransmitted on a CSS of a PDCCH. In another embodiment, the DCI format Ycan be a DCI format 1C that can be transmitted on a CSS of a PDCCH.

FIG. 5 further illustrates that for a selected UE, the TDD UL/DLconfiguration of a serving cell can be jointly coded with other TDDUL/DL configurations for other serving cells in a PDCCH with DCI formatX used for UL/DL reconfiguration indication, wherein cyclic redundancycheck (CRC) parity bits can be scrambled with a TDD-Config-RNTI assignedfor eIMTA operation. In one embodiment, where a group of UEs or multipleserving cells of a UE can receive dedicated and independent TDD UL/DLconfigurations by the same TDD-Config-RNTI, an index can be providedthat indicates the M-bit TCI fields associated with the serving cell ofthe receiving UE for the UUDL configuration indication. In oneembodiment, M can be 3, but larger or smaller TCI code words can also beused.

FIG. 6 shows a table depicting a coding of 3-bit target cell identity(TCI) code words used for TDD UL/DL configuration indication. Oneadvantage of a 3-bit TCI can be to provide a full-range flexibility forUL/DL reconfiguration.

In another embodiment, M can be 2. FIG. 7 shows a table depicting acoding of 2-bit TCI code words used for a TDD UL/DL configurationindication. For a 2-bit TCI, the UL subframes according to the TDD UL/DLconfiguration indicated in a system information block type 1 (SIB1)message can be configured as flexible subframes (FlexSF). In oneembodiment, for a 2-bit TCI, the UL/DL reconfiguration can be invisibleto legacy UEs and can enable avoiding a negative impact on a radioresource management (RRM) measurement of legacy UEs. One advantage ofusing a 2-bit TCI can be to reduce control overhead of a communicationsnetwork. In one embodiment, for each TDD UL/DL configuration indicatedin a SIB1 message, a set of UL/DL configuration associated with the2-bit TCI field can be defined for UL/DL reconfiguration indication.

In one embodiment, an information element (IE) can be aTDD-PDCCH-Config, where the TDD-PDCCH-Config can be used to specify theRNTI(s) and index(es) used for flexible UL/DL configuration indications.In one embodiment, the TDD UL/DL re-configuration function can be setupor released with the IE. In another embodiment, the IE can be aTDD-Config-RNTI, where the TDD-Config-RNTI can be an RNTI for a TDDUL/DL configuration indication using DCI format X. In anotherembodiment, the IE can be a TDD-Config-lndex with an index of K. TheTDD-Config-lndex can be a parameter used to indicate an index to the TDDUL/DL configuration field in a DCI format X associated with a servingcell of an eIMTA-enabled UE. In one example, K can be 16.

FIG. 8 illustrates a signaling flow between a UE 802 and an evolveduniversal terrestrial radio access network (EUTRAN) 804 using an RRCconnection setup message to setup a dynamic UL/DL configuration. Whenthe EUTRAN 804 does not receive the UE capabilities from the corenetwork, such as when the UE 802 is in an evolved packet system (EPS)mobility management (EMM) DEREGISTERED mode, the EUTRAN 804 can requestthat the UE 802 use a UE capability transfer procedure to provide thecapabilities of the UE 802 to the EUTRAN 804. The UE capability transfercan include step 0 (800) for establishing an RRC connection between theUE 802 and the EUTRAN 804. After establishing the RRC connection 800between the UE 802 and the EUTRAN 804, then in step 1 (810) the EUTRAN804 can send a UECapabilityEnquiry to the UE 802. After theUECapabilityEnquiry 810 is received by the UE 802, in step 2 (820) theUE 802 can send the EUTRAN 804 a UECapabilitylnformation message. TheUECapabilitylnformation message can indicate the capability of the UE802 to support TDD UL/DL re-configuration.

In one embodiment, the IE can be a PhyLayerParameters-v1240, where thePhyLayerParameters-v1240 indicates a UE capability of TDD UL/DLreconfiguration. The PhyLayerParameters-v1240 can be defined as:

-- ASN1START PhyLayerParameters-v1240 ::= SEQUENCE {   TDD-configuration-r12 ENUMERATED {supported}    OPTIONAL, } --ASN1STOP

In another embodiment, the IE can be a TDD-configuration-r12, where theTDD-configuration-r12 indicates whether the UE 802 supports a TDD UL/DLreconfiguration capability.

Steps 3-5 a of FIG. 8, show the steps for a RRC connection establishmentprocedure to transfer the parameters for the TDD UL/DL reconfigurationcapability between an eIMTA capable UE and an EUTRAN. In Step 3 (830),the UE 802 can send an RRCConnectionRequest to the EUTRAN 804. In Step 4a (840), when the EUTRAN 804 receives the UE capability of eIMTAsupport, based on a flexible TDD UL/DL configuration, an IETDD-PDCCH-Config can be included in a RRCConnectionSetup message. In oneembodiment, the RRCConnectionSetup message can include:RadioResourceConfigDedicated information, PhysicalConfigDedicatedinformation, and/or TDD-PDCCH-Config information. In one embodiment,when the TDD-PDCCH-Config IE is not included in the RRCConnectionSetupmessage, the UE 802 can follow a TDD UL/DL configuration procedure asindicated in a system information block 1 (SIB1) for Data transmissionand reception. In step 5 a (850), the UE 802 can send the EUTRAN 804 anRRCConnectionComplete message. In step 6 (860), the UE 802 can decodethe PDCCH for DCI format X detection when the UE 802 receives theTDD-PDCCH-Config message, including a TDD-Config-RNTI message and aTDD-Config-Index message. In one embodiment, the UE 802 can follow theassociated TDD UL/DL configurations indicated in the DCI format X. Inanother embodiment, the UE 802 can follow TDD UL/DL configurationindicated in a SIB1.

Step 7 (870) shows, for an SCell in a CA scenario, the E-UTRAN 804 canuse dedicated signaling to provide a TDD-PDCCH-Config IE to the UE 802that supports TDD UL/DL reconfiguration when adding the SCell. When theUE 802 receives the TDD-PDCCH-Config, UE 802 can monitor a PDCCH with aDCI format X, where the CRC is scrambled by the assignedTDD-Config-RNTI. Additionally, when the UE 802 receivesTDD-PDCCH-Config, the UE 802 can obtain a UL/DL configuration for theassociated serving cell upon receiving DCI format X on a PDCCH,according to the TDD-Config-Index. Step 8 (880) shows the UE 802 sendingthe EUTRAN 804 an RRCConnectionReconfigurationComplete message.

In one embodiment, step 7 (870), step 8 (880) and step 9 can occur for aUE capable of both Carrier Aggregation (CA) and eIMTA support when eIMTAis used in the added Secondary Cell (SCell). In one embodiment, in step9 (890), for each SCell, when the UE 802 receives a TDD-PDCCH-Configmessage in the configuration of one SCell in Step 8 the UE 802 candetermine the UL/DL configuration by decoding the associated TCI fieldin DCI format X for this SCell. In one embodiment, the TDD-PDCCH-Configmessage can include the TDD-Config-RNTI message and the TDD-Config-Indexmessage. In another embodiment, in step 9 (890), the UE 802 candetermine the UL/DL configuration upon receiving DCI format X accordingto the received TDD-Config-r10 IE of aRadioResourceConfigCommonSCell-r10 for the SCell. In one embodiment,when no TDD-Config-RNTI is received, the UE can monitor and decode thePDCCH following a UL/DL configuration indicated in SIB1.

FIG. 9 illustrates an alternative signaling flow between a UE 902 and aEUTRAN 904 using an RRC connection reconfiguration message to establisha dynamic UL/DL configuration. Steps 0 through step 2 are the same as inFIG. 8 discussed in the preceding paragraphs. FIG. 9 does not includedstep 3 as in FIG. 8. After the UE 902 sends the EUTRAN 904 aUECapabilitylnformation message in step 2, in step 4 b (940) the EUTRAN904 sends the UE 902 a RRCConnectionReconfiguration message. TheRRCConnectionReconfiguration message can include aRadioResourceConfigDedicated message and/or aPhysicalConfigDedicated::TDD-PDCCH-Config message. In Step 5 b, the UE902 sends a RRCConnectionReconfigurationComplete message to the EUTRAN904. The remaining steps in FIG. 9 are the same as the steps discussedin the preceding paragraphs for FIG. 8.

FIG. 10 illustrates a PDCCH that can be used for a DCI format Xtransmission. FIG. 10 further shows that for searching the DCI format Xwith a CRC scrambled with an assigned RNTI for eIMTA, a UE configuredwith an UL/DL reconfiguration can monitor a CSS on the PDCCH in everynon-DRX fixed DL subframe according to a UL/DL configuration indicatedin SIB1 at each of the aggregation levels 4 and 8 on a primary cell(PCell). In another embodiment, for searching the DCI format X with theCRC scrambled with the assigned RNTI for eIMTA, the UE configured withan UUDL reconfiguration can monitor a CSS on PDCCH in every non-DRXfixed DL subframe at monitoring aggregation level 8 on a PCell to reducethe blind decoding attempts.

FIG. 11 illustrates a CSS on a PDCCH that can be used for transmissionof a DCI format X. In this example, the UL/DL configuration informationfor a secondary cell (SCell) is carried on a DCI format X transmitted ona CSS of a PDCCH channel of the SCell. In one embodiment, the DCI formatX can include an UL/DL configuration indication field for differentserving cells that can be concatenated onto a DCI format X andtransmitted on a PCell of the UE. In another embodiment, the DCI formatX that includes the UL/DL configuration indication field for differentserving cell can be deconstructed and transmitted on its own commonsearch space of a PDCCH of the serving cells. FIG. 11 furtherillustrates a DCI format X indicating that the UL/DL configuration ofthe PCell is transmitted using a CSS on a PDCCH of the PCell, and theUL/DL configuration of the SCell is coded into another DCI format X thatcan be transmitted using a CSS on a PDCCH of the SCell. One advantage oftransmitting a UL/DL configuration of different cells separately (i.e.PCell and SCell) on the common search space of the different servingcells can be to ensure that the UL/DL reconfiguration is applicableirrespective of a backhaul latency between two serving cells, as shownwith the PCell and SCell in FIG. 11.

FIG. 12 illustrates a DCI format X that includes a UL/DL configurationindication field for different serving cells that is deconstructed intotwo separate DCI formats and respectively mapped onto different PDCCHchannels within a CSS of the PCell. In one embodiment, different DCIformats can be differentiated with different TDD-Config-RNTI values andwith the same DCI format sizes.

In one embodiment, the DCI format X can be transmitted using aUE-specific search space (USS) on a PDCCH or an enhanced PDCCH (EPDCCH).The PDCCH or the EPDCCH can be determined by an assignmentTDD-Config-RNTI configured by higher layer signaling, as shown in FIGS.8 and 9. In one embodiment, the location of multiple USSs associatedwith different RNTI can be on a PCell. In another embodiment, thelocation of multiple USSs associated with different RNTI can be on eachserving cell that the UUDL configuration targets, as indicated in theDCI format X.

In one embodiment, a UE-group-common search space on a PDCCH can beassociated with an assigned radio network temporary identifier (RNTI)value. For example, the RNTI value can be a TDD-Config-RNTI. For eachserving cell on that the physical downlink control channel (PDCCH) ismonitored, the control channel elements (CCEs) corresponding to a PDCCHcandidate m of a UE-group-common search space with CCE aggregation levelL in subframe k (S_(k) ^((L))) can be determined using:

L{(Y_(k)+m′)mod└N_(CCE,k)/L┘}+i

where Y_(k) is defined as:

Y_(k)=(A·Y_(k−1))mod D,

wherein i=0,L ,L−1 is a CCE index within a aggregation level L,Y⁻¹=n_(RNTI)=tdd−config−RNTI≠0, A=39827, D=65537 and k=└n_(s)/2┘, wheren_(s) is the slot number within a radio frame and an aggregation level L∈{1,2,4,8} is defined by a set of PDCCH candidates, and N_(CCE,k) is thetotal number of Control Channel Elements (CCEs) in a control region ofsubframe k. In one embodiment, in a PDCCH UE-group-common search spacefor a serving cell on which the PDCCH is monitored, when the monitoringUE is configured with a carrier indicator field thenm′=m+M^((L))·n_(CI), where n_(CI) is the carrier indicator field valueand M^((L)) is the number of PDCCH candidates to monitor in the UEspecific search space for aggregation level L. In another embodiment,when the monitoring UE is not configured with a carrier indicator fieldthen m′=m, where m=0,L,M^((L))−1 refer to the CCE index within a PDCCHwith aggregation level L. M^((L)) is the number of PDCCH candidates tomonitor in a selected search space.

FIG. 13 illustrates that when a UE is not configured for enhancedphysical downlink control channel (EPDCCH) monitoring and the UE is notconfigured with a carrier indicator field, the UE can monitor one PDCCHUE-group-common search space at each of the aggregation levels 1, 2, 4,8.

FIG. 14 illustrates that when a UE is not configured for EPDCCHmonitoring and the UE is not configured with a carrier indicator field,a subset of aggregation levels on the PCell can be monitored. In anotherembodiment each serving cell that supports UL/DL re-configurationfunctionality in non-DRX fixed DL subframes or a portion of non-DRXfixed DL subframes can be monitored. FIG. 14 further illustrates PDCCHmapping, where a UE is configured with two serving cells and eachserving cell supports UL/DL reconfiguration functionality. In oneembodiment, control channel elements (CCEs) carrying UL/DLreconfiguration PDCCH for primary cell can be transmitted in the controlregion on the primary cell (PCell). In another embodiment, the CCEscarrying UL/DL reconfiguration PDCCH for secondary cell can betransmitted in the control region of the secondary cell (SCell).

In one embodiment, UEs are configured to monitor PDCCH UE-specificsearch space (USS) for obtaining a flexible UL-DL reconfigurationinformation. In another embodiment, monitoring the reconfiguration PDCCHcarrying flexible UL-DL reconfigurations can increase the total blinddecoding attempts number at UE side because of extra search spacemonitoring, unless the number of blind detections required by the UEspecific search space on the serving cell are reduced to keep theoverall blind detection number unchanged.

In one embodiment, a UE-group-common search space on an EPDCCH can beassociated with an assigned RNTI value, such as a TDD-Config-RNTI. FIG.15 illustrates one EPDCCH physical resource block (PRB) set that isconfigured to be shared by all UEs with EPDCCH monitoring. For a commonEPDCCH-PRB-set used for DCI format X transmission, consisting of a setof enhanced control channel elements (ECCEs) numbered from 0 toN_(ECCE,p,k)−1, the ECCEs corresponding to EPDCCH candidate m of thesearch space ES_(k) ^((L)) are given by

${{L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + b} \right){mod}\left\lfloor {N_{{ECCE},p,k}\text{/}L} \right\rfloor} \right\}} + i},$

-   -   where y_(p,k)=(A·Y_(p,k−1))mod D,        Y⁻¹=n_(RNTI)=tdd−config−RNTI≠0, A=39827, A₁=39829, D=65537,        k=└n_(s)/2, and aggregation level L ∈{1,2,4,8,16,32} is defined        by a set of EPDCCH candidates, Y_(p,k) is variable ‘Y’ value in        EPDCCH-PRB-set p of subframe k, and,    -   m=0,1,K M_(p) ^((L))−1 is the ECCE index number within        aggregation level L, N_(ECCE,p,k) is the number of ECCEs in        EPDCCH-PRB-set p of subframe k, M_(p) ^((L)) is the number of        EPDCCH candidates to monitor at aggregation level L in        EPDCCH-PRB-set p for the serving cell on which EPDCCH is        monitored, and b=n_(CI) when the UE is configured with a carrier        indicator field for the serving cell on which EPDCCH is        monitored, otherwise b=0, n_(CI) is the carrier indicator field        value, and n_(s) is the slot number within a radio frame.

In one embodiment, when the UE is configured with a carrier indicatorfield for the serving cell on which the EPDCCH is monitored thenb=n_(CI), wherein n_(CI) is the carrier indicator field value. Inanother embodiment, when the UE is not configured with a carrierindicator field for the serving cell on which EPDCCH is monitored thenb=0. In one embodiment, the UE-group-common search space can benaturally distributed to obtain frequency and inference coordinationdiversity gain. In one embodiment, the UL/DL reconfiguration can besupported by a UE configured with EPDCCH monitoring.

FIG. 16 illustrates a TDD UL/DL configuration supporting for CoMPScenario 4, in which each LPN or separated RRH Cell share the samephysical cell ID with a Macro cell. In one embodiment, different TDDUL/DL configurations can be independently deployed at geographicallyseparated RRHs in a CoMP Scenario 4. In one embodiment, in the CoMPscenario 4, the transmission points within a selected coverage area of amacro transmission point can share the same cell identification (cellID), such as Cell ID 0 in FIG. 16. In one example, the transmissionpoints can be a macro cell, a pico cell, an RRH, and/or another type oflow power node (LPN).

In one embodiment, DCI format X transmissions from low power RRHs withthe same cell IDs within a macro cell coverage area can be time-domainmultiplexed by assigning the DCI format X transmissions to differentsubframe offsets. In one embodiment, the DCI format X transmissions canbe assigned a same duty cycle or different duty cycles based on datatraffic conditions or backhaul characteristic for the transmissions. Inanother embodiment, the UL/DL configuration for different RRHs in CoMPScenario 4 can be informed by separate TCI fields within a DCI format Xtransmission. The separate TCI fields within one DCI format X canprovide a second dimension for a TDD UL/DL configuration indication inaddition to a time-division multiplexing (TDM) over different subframebased solution. FIG. 16 illustrates that the UEs capable of UL/DLreconfiguration (e.g. UE 1, UE 4, etc.) but associated with differenttransmission point can be configured with independent UL/DLconfigurations depending on traffic characteristic in each individualcell of transmission points. In one embodiment, a single UL/DLreconfiguration PDCCH can be allowed to be transmitted after the UEindicates the UL/DL reconfiguration capability to a EUTRAN.

When the UEs indicate the UL/DL reconfiguration capability to a EUTRAN,a set of parameters, such as a TDD-Config-RNTI and a TDD-Config-Index,can be communicated/configured to a UL/DL reconfiguration capable UE toaid the UE to monitor the DCI format X. FIG. 17 illustrates a table withthe configurations for the TDD UL/DL reconfiguration indication. In oneembodiment, the UEs can decode a UE-group-common search space for a DCIformat X with a CRC scrambled by an assigned RNTI value (i.e.TDD-Config-RNTI). When the UE decodes the UE-group-common search space,the UE can determine a UL/DL configuration of one serving cell accordingto a corresponding TCI index value, i.e. TDD-Config-lndex, within theDCI format X.

FIG. 18 illustrates a UL/DL configuration in a CoMP Scenario 3 withenabled CA at each RRH. The UL/DL configuration in CoMP Scenario 3 withan enabled CA at each RRH can enable traffic adaption across servingcells by allowing independent UL/DL configurations among differentcarriers and geographically different RRHs for a CoMP and CA scenario.FIG. 18 further illustrates that for a CoMP Scenario 3, the RRH can beconfigured as a cell with a Cell-ID. In one embodiment, for a CoMPScenario 4 the RRH can be configured to share the same Cell-ID as amacro cell. FIG. 18 further shows seven different TDD UUDLconfigurations, ranging from TDD UL/DL configuration 0-6, which allow avariety of downlink-uplink ratios (i.e. 40% to 90% DL ratio) andswitching periodicities (i.e. 5 ms and 10 ms). As shown in FIG. 18, theserving cells deployed on carrier 0 of RRH 0 have a higher UL trafficthan that on carrier 1, so RRH 0 configured UL/DL configuration 2 onCarrier 0 while configured UL/DL configuration 5 on Carrier 1 as thelatter one provides more DL resources than the former one.

FIG. 19 shows a table with a set of TDD UL/DL configurations for a TDDUL/DL reconfiguration indication. The TDD UL/DL reconfigurationconfiguration parameters, such as RNTI or UL/DL configuration index(i.e. TDD-Config-lndex) within DCI format X can be communicated to UEs,such as UE 0 and UE 1, through higher-layer signaling. In oneembodiment, an RNTI value can be used across two RRHs for CoMP scenario3 with CA enabling. In another embodiment, two distinct RNTI values,e.g. RNTI X and RNTI Y, or different TDD-Config-lndex configurations canbe assigned to UE 0 and UE 1 to enable an independent UL/DLconfiguration for each serving cell. In one embodiment, theTDD-Config-lndex can be provided by higher layers and used to determinethe index to the UL/DL configuration for a serving cell of a selectedUE.

Another example provides functionality 2000 of computer circuitry of aUE operable to dynamically change an uplink/ downlink (UL/DL)configuration in a communications network, as shown in the flow chart inFIG. 20. The functionality can be implemented as a method or thefunctionality can be executed as instructions on a machine, where theinstructions are included on at least one computer readable medium orone non-transitory machine readable storage medium. The computercircuitry can be configured to dynamically change an uplink/ downlink(UL/DL) configuration in a communications network, as in block 2010. Thecomputer circuitry can be further configured to communicate, to theeNode B, a UE Capability Information information element (IE) toindicate an enhanced interference mitigation and traffic adaptation(eIMTA) capability of the UE to support an eIMTA time duplex domain(TDD) UL/DL reconfiguration functionality, as in block 2020. Thecomputer circuitry can be further configured to receive, at the UE,eIMTA configuration information within a RRCConnectionSetup message or aRRCConnectionReconfiguration message, as in block 2030.

In one embodiment, the RRCConnectionSetup message or theRRCConnectionReconfiguration message can include a eIMTA Radio-NetworkTemporary Identifier (RNTI) and a 2-bit or 3-bit UL/DL configurationindicator field index within the UL/DL reconfiguration physical downlinkcontrol channel (PDCCH) associated with a serving cell. In oneembodiment, the computer circuitry can be configured to attempt todecode the UL/DL reconfiguration PDCCH with a cyclic redundancy check(CRC) scrambled by the assigned eIMTA-RNTI and determine UL/DLconfiguration information from a decoded UL/DL reconfiguration PDCCHbased on an assigned indicator index.

In one embodiment, the computer circuitry can be configured to monitorone common search space (CSS) on a Primary Cell (PCell) to receive theUL/DL reconfiguration PDCCH with CRC scrambled by the eIMTA-RNTIassigned for the UE. In one embodiment, the computer circuitry can beconfigured to monitor one common search space (CSS) on a Primary Cell(PCell) to receive the UL/DL reconfiguration PDCCHs with CRCs scrambledby multiple different eIMTA-RNTIs separately, wherein each eIMTA-RNTIhas a one-to-one mapping with a serving cell index. In one embodiment,the computer circuitry can be configured to monitor common search space(CSS) on each eIMTA-enabled serving cell to receive the UL/DLreconfiguration PDCCHs with CRC scrambled by one eIMTA-RNTI assigned forthe UE.

In one embodiment, the computer circuitry can be configured to monitor aUE-group-common search space on a PDCCH on a Primary Cell (PCell) oreach eIMTA-enabled serving cell to receive the UL/DL reconfigurationPDCCHs with CRC scrambled by different eIMTA-RNTIs assigned for the UEfor each serving cell, wherein the control channel elements (CCEs)corresponding to PDCCH candidate m of the UE-group-common search spaceS_(k) ^((L)) can be determined using:

L{(Y_(k)+m′)mod└N_(CCE,k)/L┘}+i

-   -   where aggregation level L∈{1,2,4,8} can be defined by a set of        PDCCH candidates and, Y_(k) can be determined using:

Y_(k)=(A·Y_(k−1))mod D

-   -   where Y⁻¹=n_(RNTI)≠0, A=39827, D=65537 and k=└n_(s)/2┘, n_(s)        slot number within a radio frame, and the RNTI value used for        n_(RNTI) is the eIMTA-RNTI assigned for UL/DL reconfiguration        PDCCH transmission.

In one embodiment, wherein m′=m when the monitoring UE is not configuredwith a carrier indicator field.

In one embodiment, wherein m′=m+M^((L))·n_(CI), where n_(CI) is acarrier indicator field value, m=0,L, M^((L))−1, M^((L)) is a number ofPDCCH candidates to monitor in a UE specific search space foraggregation level L, N_(CCE,k) is a total number of CCEs in a controlregion of subframe k, and i=0,L,L−1 is a CCE index within a aggregationlevel L.

In one embodiment, the computer circuitry can be configured to monitorthe UE-group-common search space on an enhanced PDCCH (EPDCCH) on aPCell only when cross-carrier scheduling is configured or on eacheIMTA-enabled serving cell when cross-carrier scheduling is notconfigured, to receive the UL/DL reconfiguration PDCCHs with CRCscrambled by multiple different eIMTA-RNTIs assigned for the UE, whereinenhanced control channel elements (ECCEs) corresponding to EPDCCHcandidate m of a search space ES_(k) ^((L)) can be given by:

${{L\left\{ {\left( {Y_{p,k} + \left\lfloor \frac{m \cdot N_{{ECCE},p,k}}{L \cdot M_{p}^{(L)}} \right\rfloor + b} \right){mod}\left\lfloor {N_{{ECCE},p,k}\text{/}L} \right\rfloor} \right\}} + i},$

-   -   where Y_(p,k) is defined below and i=0,L,L−1,

Y_(p,k)=(A·Y_(p,k−1))mod D

-   -   where aggregation level L∈{1,2,4,8,16,32} is defined by a set of        EPDCCH candidates, Y_(p,k) is variable ‘Y’ value in        EPDCCH-physical resource block-set p of subframe k, and, m=0,1,K        M_(p) ^((L))−1 is an ECCE index number within aggregation level        L, N_(ECCE,p,k) is a number of ECCEs in EPDCCH-PRB-set p of        subframe k., M_(p) ^((L)) is a number of EPDCCH candidates to        monitor at aggregation level L in EPDCCH-PRB-set p for a serving        cell on which the EPDCCH is monitored, b=n_(CI) if the UE is        configured with a carrier indicator field for the serving cell        on which EPDCCH is monitored, otherwise b=0; and n_(CI) is the        carrier indicator field value.

In one embodiment, the UL/DL reconfiguration PDCCH includes N TDD UL/DLConfiguration Indicator (TCI) fields, where N can be configured by theeNode B within an RRC signaling message for each eIMTA capable UE or Ncan be determined using

${N = \left\lfloor \frac{L_{{format}\mspace{14mu} Y} - R_{others}}{M} \right\rfloor},$

wherein L_(format Y) is a payload size of an existing downlink controlinformation (DCI) format Y before CRC attachment, R_(others)≥0 is anumber of information bits used for selected functionalities, M ispayload size for each UL/DL configuration indicator within UL/DLreconfiguration PDCCH, and format Y is mapped onto a common searchspace.

In one embodiment, the selected functionalities include Transmit PowerControl (TPC) commands for physical uplink shared channel (PUSCH)transmission on flexible subframes. In another embodiment, zero-paddinginformation bits can appended to TDD UL/DL configuration indicatorfields until a UL/DL reconfiguration PDCCH size is equal to a format Ysize mapped onto the common search space.

Another example provides functionality 2100 of computer circuitry of aneNode B operable to dynamically change a time duplex domain (TDD)uplink/downlink (UL/DL) configuration in a communications network, asshown in the flow chart in FIG. 21. The functionality can be implementedas a method or the functionality can be executed as instructions on amachine, where the instructions are included on at least one computerreadable medium or one non-transitory machine readable storage medium.The computer circuitry can be configured to establish a radio resourcecontrol connection with a user equipment (UE), as in block 2110. Thecomputer circuitry can be further configured to receive, from the UE, aUE Capability Information information element (IE) to indicate anenhanced interference mitigation and traffic adaptation (eIMTA)capability of the UE, as in block 2120. The computer circuitry can befurther configured to determine support of eIMTA functionality by the UEbased on the UE Capability Information IE, as in block 2130. Thecomputer circuitry can be further configured to configure radio resourcecontrol (RRC) parameters for performing an eIMTA UL/DL reconfigurationof the UE, as in block 2140.

In one embodiment, the computer circuitry can be configured tocommunicate, to the UE, eIMTA parameters associated with a secondarycell (SCell) of the eNode B. In another embodiment, the RRC parameterscan include an eIMTA radio network temporary identities (RNTI) of the UEand an indicator index.

FIG. 22 uses a flow chart 2200 to illustrate a method for dynamicallychanging an uplink /downlink ratio in a communications network. Themethod can comprise requesting a radio resource control (RRC) connectionwith an enhanced node B (eNode B), as in block 2210. The method canfurther comprise communicating, to the eNode B, a user equipment (UE)Capability

Information message to indicate an enhanced interference mitigation andtraffic adaptation (eIMTA) capability of the UE to support an eIMTA timeduplex domain (TDD) UL/DL reconfiguration functionality, as in block2220. The method can further comprise receiving, at the UE, eIMTAconfiguration information within a RRCConnectionSetup message or aRRCConnectionReconfiguration message, as shown in block 2230.

In one embodiment, the RRCConnectionSetup message or theRRCConnectionReconfiguration message includes a eIMTA Radio-NetworkTemporary Identifier (RNTI) and a 2-bit or 3-bit UL/DL configurationindicator field index within a UL/DL reconfiguration physical downlinkcontrol channel (PDCCH) associated with a serving cell. In anotherembodiment, a UL/DL reconfiguration physical downlink control channel(PDCCH) includes N TCI fields, where N can be configured by the eNode Bwithin an RRC signaling message for each eIMTA capable UE or N isdetermined using

${N = \left\lfloor \frac{L_{{format}\mspace{14mu} Y} - R_{others}}{M} \right\rfloor},$

wherein L_(format Y) is a payload size of an existing downlink controlinformation (DCI) format Y before CRC attachment, R_(others)≥0 is anumber of information bits used for selected functionalities, M is asize of a target cell identifier (TCI) code word within the UL/DLreconfiguration PDCCH, and format Y is mapped onto a common searchspace.

In one embodiment, the existing DCI format Y mapped onto the commonsearch space can be a DCI format 1C. In another embodiment, the existingDCI format Y mapped onto the common search space can be a DCI format0/1A/3/3A. In another embodiment, the TCI code word size of M can be 3bits and each TCI code word can be a different UL/DL configuration. Inanother embodiment, the UL/DL reconfiguration PDCCH mapped onto thecommon search space can be configured to enable independent UL/DLconfigurations for each serving cell in a single carrier scenario, acoordinated multiple point (CoMP) scenario 3, a CoMP scenario 4, acarrier aggregation (CA) scenario, and a combination of a CA and CoMPscenario.

In one embodiment, the method can further comprise receiving, at the UE,eIMTA configuration parameters and an indicator index associated with asecondary cell (SCell) of the UE and determining a UL/DL configurationfor the SCell based on a received indicator index within a receivedUL/DL reconfiguration PDCCH. In another embodiment, a UL/DLconfiguration indicator field within a UL/DL reconfiguration PDCCH canbe 2 bits or 3 bits. In one embodiment, the method can further comprisetransmitting the DCI format on all system information block 1 (SIB1) DLsubframes and determining, at a discontinuous reception (DRX) UE, anUL/DL configuration when the DRX UE c in a flexible subframe.

FIG. 23 also provides an illustration of a microphone and one or morespeakers that can be used for audio input and output from the wirelessdevice. The display screen can be a liquid crystal display (LCD) screen,or other type of display screen such as an organic light emitting diode(OLED) display. The display screen can be configured as a touch screen.The touch screen can use capacitive, resistive, or another type of touchscreen technology. An application processor and a graphics processor canbe coupled to internal memory to provide processing and displaycapabilities. A non-volatile memory port can also be used to providedata input/output options to a user. The non-volatile memory port canalso be used to expand the memory capabilities of the wireless device. Akeyboard can be integrated with the wireless device or wirelesslyconnected to the wireless device to provide additional user input. Avirtual keyboard can also be provided using the touch screen.

Various techniques, or certain aspects or portions thereof, can take theform of program code (i.e., instructions) embodied in tangible media,such as floppy diskettes, CD-ROMs, hard drives, non-transitory computerreadable storage medium, or any other machine-readable storage mediumwherein, when the program code is loaded into and executed by a machine,such as a computer, the machine becomes an apparatus for practicing thevarious techniques. In the case of program code execution onprogrammable computers, the computing device can include a processor, astorage medium readable by the processor (including volatile andnon-volatile memory and/or storage elements), at least one input device,and at least one output device. The volatile and non-volatile memoryand/or storage elements can be a RAM, EPROM, flash drive, optical drive,magnetic hard drive, or other medium for storing electronic data. Thebase station and mobile station can also include a transceiver module, acounter module, a processing module, and/or a clock module or timermodule. One or more programs that can implement or utilize the varioustechniques described herein can use an application programming interface(API), reusable controls, and the like. Such programs can be implementedin a high level procedural or object oriented programming language tocommunicate with a computer system. However, the program(s) can beimplemented in assembly or machine language, if desired. In any case,the language can be a compiled or interpreted language, and combinedwith hardware implementations.

It should be understood that many of the functional units described inthis specification have been labeled as modules, in order to moreparticularly emphasize their implementation independence. For example, amodule can be implemented as a hardware circuit comprising custom VLSIcircuits or gate arrays, off-the-shelf semiconductors such as logicchips, transistors, or other discrete components. A module can also beimplemented in programmable hardware devices such as field programmablegate arrays, programmable array logic, programmable logic devices or thelike.

Modules can also be implemented in software for execution by varioustypes of processors. An identified module of executable code can, forinstance, comprise one or more physical or logical blocks of computerinstructions, which can, for instance, be organized as an object,procedure, or function. Nevertheless, the executables of an identifiedmodule need not be physically located together, but can comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposefor the module.

Indeed, a module of executable code can be a single instruction, or manyinstructions, and can even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data can be identified and illustrated hereinwithin modules, and can be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data can becollected as a single data set, or can be distributed over differentlocations including over different storage devices, and can exist, atleast partially, merely as electronic signals on a system or network.The modules can be passive or active, including agents operable toperform desired functions.

Reference throughout this specification to “an example” means that aparticular feature, structure, or characteristic described in connectionwith the example is included in at least one embodiment of the presentinvention. Thus, appearances of the phrases “in an example” in variousplaces throughout this specification are not necessarily all referringto the same embodiment.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials can be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary. In addition, various embodiments and example of the presentinvention can be referred to herein along with alternatives for thevarious components thereof. It is understood that such embodiments,examples, and alternatives are not to be construed as defactoequivalents of one another, but are to be considered as separate andautonomous representations of the present invention.

Furthermore, the described features, structures, or characteristics canbe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided, such asexamples of layouts, distances, network examples, etc., to provide athorough understanding of embodiments of the invention. One skilled inthe relevant art will recognize, however, that the invention can bepracticed without one or more of the specific details, or with othermethods, components, layouts, etc. In other instances, well-knownstructures, materials, or operations are not shown or described indetail to avoid obscuring aspects of the invention.

While the forgoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

What is claimed is:
 1. An evolved Node B (eNB) operable to transmit aphysical downlink control channel (PDCCH) to a user equipment (UE), theeNB comprising: one or more processors configured to: determine, at theeNB, a set of configuration indication fields numbered 1 to N, includedin a downlink control information (DCI) format Y carried on the PDCCH,where${N = \left\lfloor \frac{L_{{format}\mspace{14mu} Y}}{M} \right\rfloor},$L_(format) Y is equal to a payload size of the DCI format Y, and M is anumber of bits of each configuration indication field; and map, at theeNB, the DCI format Y onto the PDCCH; a transceiver configured totransmit to the UE the PDCCH with a cyclic redundancy check (CRC)scrambled by an enhanced interference mitigation and traffic adaptation(eIMTA) Radio-Network Temporary Identifier (RNTI) for the UE; and memoryconfigured to store the DCI format Y.
 2. The eNB of claim 1, wherein thetransceiver is further configured to transmit the PDCCH to the UE forreconfiguring a time division duplex (TDD) uplink and downlink (UL/DL)configuration at the UE, wherein the PDCCH is mapped to the DCI formatY, and the DCI format Y is included in a TDD UL/DL configurationindication.
 3. The eNB of claim 1, wherein the DCI format Y is a format1C.
 4. The eNB of claim 1, wherein M=3.
 5. The eNB of claim 1, whereinthe one or more processors are further configured to append one or morebits, with a predefined value of zero, to the set of configurationindication fields, until a total number of bits of the N configurationindication fields is equal to the payload size of the DCI format Y. 6.The eNB of claim 1, wherein the transceiver is further configured totransmit the eIMTA-RNTI to the UE to enable the UE to decode the PDCCH.7. The eNB of claim 1, wherein the transceiver is further configured totransmit a time domain duplex (TDD) uplink and downlink (UL/DL)configuration index to the UE using radio resource control (RRC)signaling, wherein the TDD UL/DL configuration index is for the set ofconfiguration indication fields numbered 1 to N.
 8. The eNB of claim 1,wherein the transceiver is further configured to receive a message fromthe UE that indicates that the UE supports a time division duplex (TDD)uplink and downlink (UL/DL) reconfiguration functionality.
 9. The eNB ofclaim 1, wherein the one or more processors are further configured tomap the DCI format Y onto a common search space (CSS) of the PDCCH fortransmission to the UE.
 10. A user equipment (UE) operable toreconfigure a time division duplex (TDD) uplink and downlinkconfiguration, the UE comprising: a transceiver configured to: receive,at the UE, an uplink and downlink (UL/DL) configuration indication froman eNB for a TDD reconfiguration, the UL/DL configuration indicationcomprising a set of configuration indication fields numbered 1 to N,included in a downlink control information (DCI) format Y carried on aphysical downlink control channel (PDCCH), where${N = \left\lfloor \frac{L_{{format}\mspace{14mu} Y}}{M} \right\rfloor},$L_(format Y) is equal to a payload size of the DCI format Y, and M is anumber of bits of each configuration indication field; and receive, atthe UE, an encoded PDCCH from the eNB, wherein the DCI format Y ismapped onto the PDCCH, wherein the PDCCH is encoded with a cyclicredundancy check (CRC) scrambled with an enhanced interferencemitigation and traffic adaptation (eIMTA) Radio-Network TemporaryIdentifier (RNTI) for the UE; and memory configured to store the UL/DLconfiguration indication.
 11. The UE of claim 10, wherein the DCI formatY is a format 1C.
 12. The UE of claim 10, wherein M=3.
 13. The UE ofclaim 10, wherein one or more bits are appended, with a predefined valueof zero, to the set of configuration indication fields, until a totalnumber of bits of the N configuration indication fields is equal to thepayload size of the DCI format Y.
 14. The UE of claim 10, wherein thetransceiver is further configured to receive a time domain duplex (TDD)uplink and downlink (UL/DL) configuration index from the eNB using radioresource control (RRC) signaling, wherein the TDD UL/DL configurationindex is for the set of configuration indication fields numbered 1 to N.15. The UE of claim 10, wherein the transceiver is further configured totransmit a message to the eNB that indicates that the UE supports a TDDUL-DL reconfiguration functionality.
 16. A user equipment (UE) operableto modify an uplink/ downlink (UL/DL) configuration, the UE comprising:a transceiver configured to: send, to an eNodeB, a request for a radioresource control (RRC) connection with the eNodeB, transmit, to theeNodeB, a UE Capability information element (IE) that indicates anenhanced interference mitigation and traffic adaptation (eIMTA)capability of the UE to support an eIMTA time duplex domain (TDD) UL/DLreconfiguration functionality; and receive, from the eNodeB, eIMTAconfiguration information via a radio resource control (RRC) message inresponse to transmitted the UE Capability IE from the UE to the eNodeB,wherein the RRC message includes an eIMTA Radio-Network TemporaryIdentifier (RNTI); and memory configured to store the eIMTAconfiguration information.
 17. The UE of claim 16, further comprisingone or more processors configured to: attempt to decode an UL/DLreconfiguration PDCCH with a cyclic redundancy check (CRC) scrambled bythe assigned eIMTA-RNTI, and determine UL/DL configuration informationfrom a decoded UL/DL reconfiguration PDCCH based on the assignedindicator field index.
 18. The UE of claim 17, wherein the UL/DLreconfiguration PDCCH includes N TDD UL/DL Configuration Indicator (TCI)fields, where N is determined using${N = \left\lfloor \frac{L_{{format}\mspace{14mu} Y} - R_{others}}{M} \right\rfloor},$wherein L_(format Y) is a payload size of an existing downlink controlinformation (DCI) format Y before CRC attachment, R_(others)≥0 is anumber of information bits used for selected functionalities, M ispayload size for each UL/DL configuration indicator field within UL/DLreconfiguration PDCCH, and format Y is mapped onto a common searchspace.
 19. The UE of claim 18, wherein zero-padding information bits areappended to TDD UL/DL configuration indicator fields until a UL/DLreconfiguration PDCCH size is equal to a format Y size mapped onto thecommon search space.
 20. The UE of claim 16, further comprising one ormore processors configured to monitor one common search space (CSS) on aPrimary Cell (PCell) to receive the UL/DL reconfiguration PDCCH with CRCscrambled by the eIMTA-RNTI assigned for the UE.